Imagine a scenario is which 104 protons are pumped across the membrane of the inner mitochondrial...

Imagine a scenario is which 104 protons are pumped across the membrane of the inner mitochondrial membrane. If you assume that the glycerol-3-phosphate shuttle is used, and the overall yield of substrate-level phosphorylations is 5,
1. Describe what role the electrons play and describe the general movement of the electrons through the electron transport chain to the final electron acceptor. (5 pts)
2. What would the effect of adding dinitrophenol (DNP) be on the electron transport chain? Be specific. (3 pts)
3. How many total ATP would be made under aerobic conditions starting at the molecule you determined? (5 pts)
4. Finally, how many protons would be pumped from your starting molecule under anaerobic conditions and why? (2 pts)

Expert Solution

Answer to above question

a) An electron transport chain (ETC) is a site of oxidative phosphorylation is found on the inner mitochondrial membrane. It is a series of complexes that transfer electrons from electron donors to electron acceptors via redox (both reduction and oxidation occurring simultaneously) reactions, and couples this electron transfer with the transfer of protons (H+ ions) across a membrane.

Flow and role of electron is as follows -

NADH+H^+ COMPLEX I QCOMPLEX III CYTOCHROME C COMPLEX IV HO

COMPLEX II

SUCCINATE

Complex I - Here two electrons are carried to the first complex aboard NADH. This complex, labeled I, is composed of flavin mononucleotide (FMN) and an iron-sulfur (Fe-S)-containing protein. The enzyme in complex I is NADH dehydrogenase and is a very large protein and it can pump four hydrogen ions across the membrane from the matrix into the intermembrane space, and it is in this way that the hydrogen ion gradient is established and maintained between the two compartments separated by the inner mitochondrial membrane.

Q and Complex II - Complex II receives FADH2, which does not pass through complex I. Compound connecting the first and second complexes to the third is ubiquinone (Q).When it is reduced, (QH2), ubiquinone delivers its electrons to the next complex in the electron transport chain. Ubiquinone receives the electrons derived from NADH from complex I and the electrons from FADH2 from complex II, including succinate dehydrogenase.These electrons bypass and thus do not energize the proton pump in the first complex, fewer ATP molecules are made from the FADH2 electrons.

Complex III - Third complex is comprises of cytochrome b, another Fe-S protein, Rieske center (2Fe-2S center), and cytochrome c proteins; this complex is also called cytochrome oxidoreductase. Complex III pumps protons through the membrane and passes( allow it to move) its electrons to cytochrome c for transport to the fourth complex of proteins and enzymes.

Complex IV - Fourth complex is made up of cytochrome proteins c, a, and a3. Complex contains two heme groups and three copper ions. The cytochromes takes up an oxygen molecule very tightly between the iron and copper ions until the oxygen is completely reduced. This reduced oxygen picks up two hydrogen ions from the surrounding medium to make water (H2O). Removal of the hydrogen ions from the system contributes to the ion gradient used in the process of chemiosmosis.

b) Compound 2,4-dinitrophenol (DNP) acts as ionophore(proton) , it binds protons on one side of a membrane, and being fat-soluble it travels to the opposite side where it loses the protons and thus disturbs proton gradient reducing ATP Synthesis.So what we eat is used in ATP synthesis and we reduce weight too slowly slowly.So DNP will act as a inhibitor for syntheis of ATP and thus could be dangerous for life.

gladiator answered 2 years ago

Imagine a scenario is which 52 protons are pumped across the membrane of the inner mitochondrial...

Imagine a scenario is which 52 protons are pumped across the membrane of the inner mitochondrial membrane. If you assume that the glycerol-phosphate shuttle is used, and the overall yield of substrate-level phosphorylations is 3, a. What specific starting molecule in the metabolic pathways we studied would you start with to give such a yield of pumped protons and substrate level phosphorylations? b. At what specific reactions (give the reaction, not just a “number”) in the metabolic pathways would you...

1. Which of components of the electron transport chain directly move protons across the inner mitochondrial...

1. Which of components of the electron transport chain directly move protons across the inner mitochondrial membrane? 2. Consider fermentation. How much ATP is generated during fermentation? How does the amount of ATP generated by fermentation compare to aerobic respiration? In humans, why can't fermentation sustain life? (Hint: Think of two reasons—one is related to the product of fermentation and what happens if it accumulates.) 3. Given this segment of a double-stranded DNA molecule, draw the two major steps involved...

During the transfer of two electrons from NADH to O2, protons pumped across the membrane to...

During the transfer of two electrons from NADH to O2, protons pumped across the membrane to establish the electrochemical gradient. The amount of energy from previous problem consumed for maintaining membrane potential deltaY and gradient of protons across the membrane. Calculate the ratio of proton concentrations across the inner mitochondrial membrane, if the membrane potential was measured at 37 degrees C to be deltaY= 2.0 V.

Explain the Proton-Motive force across the Inner mitochondrial membrane that both generates the H= gradient and...

Explain the Proton-Motive force across the Inner mitochondrial membrane that both generates the H= gradient and aids In pulling H+ back Into the mitochondria matrix

The mitochondrial inner membrane is impermeable to CoA and acylCoA. However, β-oxidation occurs in the mitochondrial matrix.

The mitochondrial inner membrane is impermeable to CoA and acylCoA. However, β-oxidation occurs in the mitochondrial matrix. AcylCoA is formed in the ________, and the acyl group is transferred to ______, which can cross the inner membrane through a translocase, and the acylCoA is regenerated in the _________.

a) Sketch a model for the electron-transport pathway in the mitochondrial inner membrane. Show the pathways...

a) Sketch a model for the electron-transport pathway in the mitochondrial inner membrane. Show the pathways of the electrons transport from the reduced forms of coenzyme in the mitochondrial electron-transport chain. What is the functional role of electron transport system in metabolism? b) What is an uncoupler or uncoupling agent? Provide an example of an uncoupling agent.

A pH gradient exists between the internal and external surfaces of the inner mitochondrial membrane of...

A pH gradient exists between the internal and external surfaces of the inner mitochondrial membrane of 1.4 pH units, where the external side is more acidic. a. If the membrane potential is 0.6 V (where the internal side is negative), what is the free energy change on transporting 1 mol of protons across the membrane from outside to inside at 298 K? b. Under standard state conditions, how many protons must be transported to provide enough free energy for the...

You can create a vesicle from the inner mitochondrial membrane that includes a functional ATP synthase...

You can create a vesicle from the inner mitochondrial membrane that includes a functional ATP synthase protein with its fully functional F0 rotor, central stalk, and F1 ATPase head. There is ATP, ADP, and Pi (inorganic phosphate) present inside and outside of the vesicle. You are allowed to mechanically spin the F0 rotor domain in the absence of protons. How would ATP levels change inside the vesicle? Briefly explain how this change occurs.

954.Uncouple proteins can dissipate the proton gradient (or cause leakage of protons) in the inner membrane...

954.Uncouple proteins can dissipate the proton gradient (or cause leakage of protons) in the inner membrane of mitochondria and thus decrease the membrane potential. As a result, more ATP molecules are synthesized and electron transport is stimulated.True/False? 953.Muscle lacks glucose-6-phosphatase and therefore glucose-6-phosphate cannot be dephosphorylated in muscle for export into the blood. Muscle stores glycogen for its use and muscle glycogen serve as a source of readily available fuel particular during the period of muscle exertion or physical exercise.True/False?...

Fill in the blanks about each of the following sequential steps of the electron transfer chain (ETC) of the inner mitochondrial membrane.

Fill in the blanks about each of the following sequential steps of the electron transfer chain (ETC) of the inner mitochondrial membrane.a. The initial electron donor of the ETC is _______________, which hands its two electrons off to FMN, within Complex I.b. Electrons from both Complex I and Complex II are ultimately donated to the same molecule, ____________.c. Within Complex III, electrons from ubiquinol are ultimately donated to ______________, which then passes those electrons on to Complex IV.d. ______________ is...

Question